The present invention relates to comparison circuits.
It is known to provide a window addressable memory (WAM) in which pairs of upper and lower limits of data (i.e., a window of data) are stored. This stored window may then be compared with an input data word; if the data word falls within the limits of the window, the WAM provides an output indicating the match. With known memories of this type, it is necessary to use the entire window to express the limits necessary to detect an exact match or a single limit (i.e., a threshold). A memory which detects an exact match is referred to as a content addressable memory (CAM).